Apparatus, such as that disclosed in U.S. Pat. No. 3,664,791, granted to G. W. Brown on May 23, 1972, has been provided heretofore for successively delivering a heated thermoplastic sheet to a sheet heating station, then to a forming station at which opposed die parts engage the sheet to differentially pressure form three dimensional articles in the sheet, and then to a trim station at which the articles are severed from the sheet. U.S. patent application Ser. No. 142,241, filed by Gaylord W. Brown on Apr. 21, 1980, entitled High Speed Trim Press, discloses a trim press for severing articles, which have been differentially pressure formed in a thermoplastic sheet, from the thermoplastic sheet.
U.S. patent application Ser. No. 073,690, entitled Dynamically Balanced Trim Press, filed by Gaylord W. Brown on Sept. 10, 1979, now U.S. Pat. No. 4,313,358, which is incorporated herein by reference, discloses a reciprocally movable trim die assembly including hollow cylindrical die knives and an opposed reciprocally moving trim die having trim punches which move between remote positions in which the sheet is indexed to the trim station and sheet trimming positions, engaging opposite sides of the sheet, to trim articles positioned at the trim station. The latter mentioned patent application discloses articles ejectors mounted in the follow die punches for movement relative thereto between retracted positions received by the die punches, when the die assemblies are in the spaced apart positions, and advanced, ejector positions, projecting from the hollow punches after the articles are severed from the sheet.
The ejectors disclosed in the aforementioned patent application Ser. No. 073,690 are driven via a cam and cam follower assembly which essentially "hammers" the ejector to the projected, ejecting position. Such "hammering" causes substantial loading, which can have a dilatorious effect on the machine bearings.
The ejector disclosed in the aforementioned patent application Ser. No. 073,690 moves the severed part into an opening provided in the hollow trim die knife. It is important that the severed parts be ejected as rapidly as possible and removed from the trimming station so that the plastic sheet can be rapidly indexed to advance another part to the trim station. Accordingly, it is an object of the present invention to provide a trim press of the type described for severing three dimensional articles from a sheet including mechanism for more rapidly ejecting the article severed at the trim station.
It is another object of the present invention to provide trim press apparatus having relatively movable die parts which move between spaced apart positions and sheet trimming positions for severing articles from a plastic sheet including a variable speed reciprocally mounted article ejector which moves between a retracted position and an ejector position to more rapidly eject the severed articles and maximize the speed of operation.
Yet another object of the present invention is to provide a trim press of the type described including mechanism for moving one of the trim die parts through a predetermined reciprocal stroke and new and novel amplifier mechanism for moving an article ejector through a greater predetermined stroke to eject the article and move it from a position between the die parts to a position received by the opposing die part.
Still another object of the present invention is to provide a trim press of the type described including a drive member which moves in an endless path of travel, a coupling arm which couples the drive member to a first trim die to reciprocally move the trim die toward and away from an opposing die, an ejector mounted on the moving trim die, and apparatus, mounted on the coupling arm, for moving the ejector relative to the first trim die.
A further object of the present invention is to provide a trim press of the type described including drive mechanism for relatively moving opposing trim dies and amplifying mechanism mounted on the drive mechanism for moving an ejector, carried by one moving trim die, a distance greater than the distance which the one moving trim die moves to separate the part from the one moving trim die and move it toward the other trim die.
A still further object of the present invention is to provide a trim press of the type described including a rotatable drive member mounting an eccentrically driven pin, a coupling arm which couples the eccentrically moving pin to a trim die for reciprocally moving the trim die in a reciprocal path toward and away from an opposed die, an ejector movably mounted on the moving trim die, and apparatus for moving the ejector relative to the trim die including a second pin eccentrically mounted on the first mentioned eccentrically moving pin, a rocker arm pivotally mounted on the coupling arm, and a connecting rod coupling the second eccentric pin and the rocker arm.
It is another object of the present invention to provide a trim press including a movable trim die, an ejector mounted on the trim die for movement relative thereto, an eccentrically driven pin for moving the trim die, and a second eccentric pin, mounted on the first mentioned eccentric pin for moving the ejector mechanism relative to the trim die.
Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.